Spring how to resolve entity uri in #RepositoryRestController - spring

Question

I'm using Spring boot 1.5.3, Spring Data REST, Spring HATEOAS. Spring Data REST is amazing and does a perfect job, but sometimes it's needed custom business logic and therfore I need to create a custom controller.
I'm going to use a #RepositoryRestController to benefit of Spring Data REST functionality (http://docs.spring.io/spring-data/rest/docs/current/reference/html/#customizing-sdr.overriding-sdr-response-handlers).
Because Spring Data REST use HATEOAS by default, I'm using that. I need a controller like this:
#RepositoryRestController
#RequestMapping(path = "/api/v1/workSessions")
public class WorkSessionController {
#Autowired
private EntityLinks entityLinks;
#Autowired
private WorkSessionRepository workSessionRepository;
#Autowired
private UserRepository userRepository;
#PreAuthorize("isAuthenticated()")
#RequestMapping(method = RequestMethod.POST, path = "/start")
public ResponseEntity<?> start(#RequestBody(required = true) CheckPoint checkPoint) {
Authentication auth = SecurityContextHolder.getContext().getAuthentication();
if (checkPoint == null) {
throw new RuntimeException("Checkpoint cannot be empty");
}
if (workSessionRepository.findByAgentUsernameAndEndDateIsNull(auth.getName()).size() > 0) {
// TODO return exception
throw new RuntimeException("Exist a open work session for the user {0}");
}
// ...otherwise it's opened a new work session
WorkSession workSession = new WorkSession();
workSession.setAgent(userRepository.findByUsername(auth.getName()));
workSession.setCheckPoint(checkPoint);
workSession = workSessionRepository.save(workSession);
Resource<WorkSession> resource = new Resource<>(workSession);
resource.add(entityLinks.linkFor(WorkSession.class).slash(workSession.getId()).withSelfRel());
return ResponseEntity.ok(resource);
}
}
Because the parameter CheckPoint must be an existant resource, I want the client send the link of the resourse (like you can do in Spring Data REST POST methods).
Unfortunately when I try to do that, server side I receive an empty CheckPoint object.
I already read Resolving entity URI in custom controller (Spring HATEOAS) and converting URI to entity with custom controller in spring data rest? and expecially Accepting a Spring Data REST URI in custom controller.
I'm wondering if there is a best practice to do this avoiding to expose id to the client, followind so the HATEOAS principles.

Answer 1

Try to change you controller like this:
#RepositoryRestController
#RequestMapping(path = "/checkPoints")
public class CheckPointController {
//...
#Transactional
#PostMapping("/{id}/start")
public ResponseEntity<?> startWorkSession(#PathVariable("id") CheckPoint checkPoint) {
//...
}
}
That will mean: "For CheckPoint with given ID start new WorkSession".
Your POST request will be like: localhost:8080/api/v1/checkPoints/1/start.